Here's a two-for-one political disaster, a way to miss the mark while wasting taxpayer funds. Begin with a premise — welfare recipients often use drugs — and build state law based on it. Never mind if the belief has been discredited elsewhere. And that costly constitutional challenges to random drug testing are well established in case law.

Here's a two-for-one political disaster, a way to miss the mark while wasting taxpayer funds.

Begin with a premise — welfare recipients often use drugs — and build state law based on it.

Never mind if the belief has been discredited elsewhere. And that costly constitutional challenges to random drug testing are well established in case law.

Kansas is among the latest states with a proposal to drug-test welfare recipients, with expulsion for too many positive results.

No one likes the idea of welfare recipients using drugs. Besides the use of taxpayer money, drug habits undercut achieving self-sufficiency or harm children in the household.

But patriarchal legislative approaches assume a lot, ignore a lot more and can wind up costing more than they save.

It’s pretty easy for most people to conjure the image of the lazy, crack-addicted mother abusing food stamps. That’s the problem.

Evidence exists that taxpayers, that is, the general public, use drugs at higher rates than welfare recipients. And where drugs are a problem, it’s often combined with other factors.

Florida provides the most often-cited example. The state passed such testing last year. Preliminary findings showed 2 percent of people getting aid failed the tests. And 96 percent passed, meaning the state had to eat the costs of their tests.

People who didn’t test clean had to pay for the test. That’s the plan in Kansas too, under a recently introduced bill.

Wanting to help people become self-sufficient is often behind such laws. Good objective. Wrong approach.

As a 2004 study and policy paper by the National Poverty Center concluded:

“While substance use, abuse, and dependence are barriers to self-sufficiency, so are poor education, lack of transportation, physical and mental health problems, and many other difficulties that are more common than substance abuse among welfare recipients.”

Even if all welfare recipients stopped using illicit drugs, society would see little decline in welfare rolls, the study found.

In other words, if legislators really want to help people on welfare become self-sufficient, they would stop focusing on pee cups and put more effort into job training, mental health assistance and increasing bus lines.

Expect testimony soon where some social worker will recount a horrible case example of a welfare recipient abusing the system while high on cocaine.

Argument by anecdote is a dangerous way to create new law. Go to the existing data, the results in other states, instead.

These measures often stem from an attitude of “we know what’s best for these people.”

But in backing these plans, legislators more often give evidence of what they don’t know.